This should do the trick (untested), just add them one by one:
for (CCNode* node in [oneNode.children copy])
{
[node removeFromParent];
[anotherNode addChild:node];
}
The copy is needed to avoid mutating the children array while
enumerating it. Alternatively you could also use the
reverseObjectEnumerator. Removing the node must be done so addChild:
won't complain about the node alread

With the help of AMI289 (see comments), we figured out how to repair
this.
First, I went to the project settings, and under General I removed the
text from "Launch Screen File". Then, I added Launch Image Source.
Afterwards, I removed the launch image set file and created new one.
This made the menuImage fit the whole screen in correct resolution.
Note: This might work only when using launch ima

The method to create a physics body from a collection of bodies
requires an array of physics body objects; you are passing it an array
of sprites. To fix this issue, change the method call to
let box =
SKPhysicsBody(bodies:[base.physicsBody,side1.physicsBody,side2.physicsBody])

Here's a SpriteKit-friendly way to draw random lines on a background
image. The basic steps are
Create a blank image
Convert the image to an SKTexture
Create a sprite with the texture
Draw a random line on the image
Update the sprite's texture with the image
Wait for 0.1 seconds
Iterate over steps 4-6
In GameScene.m, add the following
-(void)didMoveToView:(SKView *)view {
self.scaleMode